This invention relates to structured packing for an exchange column, and, particularly, for a mass transfer column such as a cryogenic rectification column.
Various types of exchange columns have been known in which a gas and a liquid come into contact with one another, generally in countercurrent flow. It is common to use packing elements formed of corrugated sheets or plates which contact one another and are disposed in parallel to the column axis to encourage contact between the liquid and gas. In such cases, the folds or corrugations of the plates are disposed at an angle to the column axis. Additionally, improvements have been made to structured packing to decrease the gas flow resistance in the lower region of a structured packing section, thus increasing the packing capacity. More specifically, the pressure drop associated with the gas or vapor entry into the structured packing section is made to be less than the pressure drop which would be experienced if the configuration of the structured packing in the lower region had the same configuration as in the upper portion of the structured packing section. Such improvements are described in U.S. Pat. No. 5,632,934. This patent contemplates a bulk region and a base region. The patent discloses the base region having various configurations to reduce the pressure drop therein.
A packing structure is needed which has further increased performance characteristics.
Accordingly, it is an object of the present invention to provide a packing section whose geometry can be varied in a base region, a top region, or both, to accomplish various performance requirements of a column.
A further object of the present invention is to provide a packing section wherein surface texturing is selectively used throughout the packing section to provide the desired performance of the column.
Accordingly, the present invention provides for a packing section, including a plurality of vertically oriented, diagonally-cross-corrugated packing sheets defining a section height. The section height has a base region, a bulk region, and a top region. The base region has a first particular geometry different from the geometry of the bulk region. The top region has a second particular geometry different from the geometry of the bulk region, and different from the first geometry of the base region.
The invention further includes a packing section having a plurality of vertically oriented, diagonally cross-corrugated packing sheets defining a section height. The section includes a base region, a bulk region, and a top region. The bulk region includes surface texturing. Further, at least a portion of at least one of the base region and the top region does not have surface texturing.
The invention further provides for a packing section having a plurality of vertically oriented, diagonally cross-corrugated packing sheets defining a section height. The section has a base region, a bulk region, and a top region. The bulk region includes generally horizontal fluting. Further, at least a portion of at least one of the base region and the top region includes generally vertical fluting.
Additional objects, advantages, and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention.